The official total is in for yesterday's storm, and it's 2.9" for Washington DC. A testament to the fluffiness of the snow is the fact that the total liquid precipitation was only 0.17", giving a ratio much higher than the 10:1 rule-of-thumb. Since CapitalWeather consistently predicted 2-4" for the immediate metro area, I think we did quite well, indeed. This is especially true considering what you may have seen in the so-called MSM (mainstream media) about "a storm with the potential to heap as much as eight inches of snow". On a personal note, I must say I had my doubts around 4pm yesterday, when there was only a minor fraction of an inch on the ground and bupkis in the air outside the Afternoon Blog Central computer room. We usually banish geeky stuff like "positive vorticity advection" to the comment area, so suffice it to say that an energetic area in the wind flow through the middle layers of the atmosphere helped to promote the vertical motion necessary to prolong the snowfall into the wee-most hours of the morning. National was still reporting light snow as late as 4am.

Here is Jason's own assessment of the results. I think he's being a bit hard on himself for what was an excellent forecast.

Overall, we are pleased with how we handled this storm. We first identified the potential almost a week in advance and correctly characterized its potential impact. Our accumulation forecast of 2-4" for the DC area was on target -- first posted nearly 48 hours prior to the event and before any other media or forecasting outlet. Importantly, we stuck to this forecast -- providing a consistent story about what we thought would happen. Had circumstances necessitated changing the forecast, we would have. But, despite flip flopping in the models, we saw no physical basis to change our forecast.

Of course, we didn't do everything perfectly. I overreacted to a model run Friday night and implied there was a real chance the snow would not materialize. I retracted that on Saturday, and fortunately was much more consistent in the 48 hours leading up to the storm. Also, our snowfall accumulation map was overdone in parts of southeast and southwest Virginia. Finally, the snow lasted a bit longer than we expected, and the bulk of the snow fell a little later than we and the models expected. Perhaps we could've recognized this by better assessing the overall dynamics and considering past events .

We're looking forward to tackling the next event.

See Matt's post below for early indications on that next event (late Thursday/Friday).

Tonight and Tomorrow

For tonight, we can expect clear skies with light winds and lows around 26 in the city, down to 18-20 in the colder 'burbs. Tomorrow will be sunny with a few passing clouds and highs around 40-42.

So says Epsilon, which is just barely hanging on to the title of hurricane as it treks on an unusual southwesterly course toward warmer latitudes, but expected weakening because of upper-level winds. A scan of the records shows that even Lili of 1984, which appears to have been the longest-lived December hurricane (total storm life 12 days), maintained hurricane strength for slightly less than 3 days. Epsilon has been a hurricane most of the time since last Friday morning.

Holiday Gift Guide: Four Seasons of Washington

Previous editions of our holiday gift guide have featured several weather calendars. If you have seen and admired the spectacular DC weather photography of CapitalWeather's own Kevin Ambrose, and you want something with a local connection, you should check out his new photo galleries highlighting the four seasons of Washington. There are print sets for lightning, cherry blossoms, and sunrise/sunsets, as well as new autumn and winter shots.

About

This site is the archive for capitalweather.com, a website specializing in Washington DC weather, forecast, and climate information, actively maintained from 2004 through 2008. In 2008, we moved to the Washington Post and continued work as the Capital Weather Gang. You can find links to our current incarnation below. Thanks for browsing.